I eliminated the whole charcoal canister system on my 20V ST swap, so I plugged the " u " shaped line from where the fuel pump is bolted on with a rubber hose and a bolt with clamps, is this fine ? I didn't think about the fuel vapors building up and preventing me from putting fuel in the gas tank in the future. I still have a long way from cranking and starting the engine, but can anyone give me some advice ? I have searched all over google and club4ag for an answer. Thank you for your help and your time.

You are going to have to vent the tank, either thru the gas cap or a breather. Air has to displace the fuel being pumped to the engine. You can probably use the current line already in the car and just run it to your air cleaner. Dave W

You have to vent or you'll run into problems. What happened to me is you'll have fuel puking out the gascap when the pressure rises high enough, which it will. You can avoid filling gas too high, but it'll still be a problem. What I did was instead of the charcoal canister, I installed a relief and safety valve and finally capped with a K&N filter. I forget exactly where I got the parts, it was a racing supply place. The relief valve is a two way valve, under low vacuum it opens to allow fuel flow. That shouldn't be much of a problem because the gas cap does this too. Under pressure, it also opens to vent pressure. The gas cap does this too, but under much higher pressure than this valve. The safety valve I have just in super remote case, if it gets inverted, as in car flips, it closes to stop fuel from coming out the vent.Don't know if it was worth all the trouble, but it allowed me to get rid of a lot of vacuum lines and hoses on my 20V.OK, here a pic from my website:The parts I ordered from Fuel Safe Racing Cells, TVP8 and TRL7. Not exactly cheap, but were talking gasoline.

Thank you taroroot ! After more thinking, I actually think your idea is the best one. I actually found that same pic when I was searching google after posting my comment here. For some reason it didn't appear on my club4ag search. I actually already ordered that Newton TPV8 valve. I have read of people leaving the line venting to atmosphere, but this is a really bad idea. Supposedly, ethanol attracts water (gas has around 10% ethanol), not sure if this is true, but either way, moisture will find its way into your gas tank if you have openings of any kind. Not sure what would actually happen in the long run if I routed the line to the air cleaner. With the TPV8 valve on the other hand, I'm completely worry free. Thank you everyone for your help, I immensely appreciate it ! ! !